1 files changed, 74 insertions, 16 deletions

diff --git a/ocaml/lib/nock.ml b/ocaml/lib/nock.ml
index 670b12b..28cecf9 100644
--- a/ocaml/lib/nock.ml
+++ b/ocaml/lib/nock.ml
@@ -64,14 +64,65 @@ let rec nock_on bus fol =
 
         | 2 ->
             (* *[subject formula new_subject] - evaluate with new subject *)
+            (* C evaluates tail first, then head - must match this order! *)
             if not (is_cell gal) then (
               if should_trace then Printf.eprintf "[Nock:%d] Op2: gal not cell\n%!" !trace_depth;
               raise Exit
             );
-            let b_gal = head gal in
             let c_gal = tail gal in
-            let seb = nock_on bus b_gal in
-            let nex = nock_on bus c_gal in
+            let b_gal = head gal in
+
+            (* Debug: log what formulas we're evaluating *)
+            if should_trace && !trace_depth <= 2 then begin
+              Printf.eprintf "[Nock:%d-DEBUG] Op2 about to evaluate:\n%!" !trace_depth;
+              Printf.eprintf "  b_gal (for subject): %s\n%!"
+                (if is_cell b_gal then
+                  let h = head b_gal in
+                  if is_atom h then
+                    (match h with Atom n -> "[" ^ Z.to_string n ^ " ...]" | _ -> "[?]")
+                  else "[cell ...]"
+                else "not-cell");
+              Printf.eprintf "  c_gal (for formula): %s\n%!"
+                (if is_cell c_gal then
+                  let h = head c_gal in
+                  if is_atom h then
+                    (match h with Atom n -> "[" ^ Z.to_string n ^ " ...]" | _ -> "[?]")
+                  else "[cell ...]"
+                else "not-cell")
+            end;
+
+            let nex = nock_on bus c_gal in  (* Tail first like C *)
+
+            if should_trace && !trace_depth <= 2 then begin
+              Printf.eprintf "[Nock:%d-DEBUG] Op2 computed formula:\n%!" !trace_depth;
+              Printf.eprintf "  nex opcode: %s\n%!"
+                (if is_cell nex then
+                  let h = head nex in
+                  if is_atom h then
+                    (match h with Atom n -> Z.to_string n | _ -> "?")
+                  else "cell"
+                else "atom")
+            end;
+
+            let seb = nock_on bus b_gal in  (* Head second like C *)
+
+            if should_trace && !trace_depth <= 2 then begin
+              Printf.eprintf "[Nock:%d-DEBUG] Op2 FINAL CHECK:\n%!" !trace_depth;
+              Printf.eprintf "  seb (subject) from b_gal=[0 %s]\n%!"
+                (match b_gal with
+                | Cell (Atom _, Atom n) -> Z.to_string n
+                | _ -> "?");
+              Printf.eprintf "  nex (formula) from c_gal=[0 %s], nex opcode = %s\n%!"
+                (match c_gal with
+                | Cell (Atom _, Atom n) -> Z.to_string n
+                | _ -> "?")
+                (if is_cell nex then
+                  let h = head nex in
+                  if is_atom h then (match h with Atom n -> Z.to_string n | _ -> "?")
+                  else "cell"
+                else "NOT-A-CELL!")
+            end;
+
             nock_on seb nex
 
         | 3 ->
@@ -165,21 +216,28 @@ let rec nock_on bus fol =
 
         | 10 ->
             (* hint - in reference implementation, hints are mostly ignored *)
-            if should_trace then Printf.eprintf "[Nock:%d] Op10: hint (gal is %s)\n%!" !trace_depth
-              (if is_cell gal then "cell" else "atom");
+            (* Two forms: [10 [[b c] d]] and [10 [b c]] *)
+            if not (is_cell gal) then (
+              if should_trace then Printf.eprintf "[Nock:%d] Op10: gal not cell\n%!" !trace_depth;
+              raise Exit
+            );
+            let p_gal = head gal in  (* First part: hint tag or [tag value] *)
+            let q_gal = tail gal in  (* Second part: formula *)
+
+            (* Determine which form we have *)
             let nex =
-              if is_cell gal then begin
-                (* [[hint-tag hint-value] formula] *)
-                let hint_part = head gal in
-                let formula = tail gal in
-                if should_trace then Printf.eprintf "[Nock:%d] Op10: hint_part is %s, formula is %s\n%!" !trace_depth
-                  (if is_cell hint_part then "cell" else "atom")
-                  (if is_cell formula then "cell" else "atom");
-                formula
+              if is_cell p_gal then begin
+                (* Form 1: [10 [[b c] d]] - full hint with value *)
+                (* p_gal = [b c], q_gal = d (formula) *)
+                if should_trace then Printf.eprintf "[Nock:%d] Op10: full hint, formula is %s\n%!" !trace_depth
+                  (if is_cell q_gal then "cell" else "atom");
+                q_gal  (* Execute the formula, ignore hint *)
               end else begin
-                (* [hint-tag formula] where hint-value is implicit *)
-                if should_trace then Printf.eprintf "[Nock:%d] Op10: implicit hint\n%!" !trace_depth;
-                gal
+                (* Form 2: [10 [b c]] - hint with implicit value *)
+                (* p_gal = b (hint tag), q_gal = c (formula) *)
+                if should_trace then Printf.eprintf "[Nock:%d] Op10: simple hint, formula is %s\n%!" !trace_depth
+                  (if is_cell q_gal then "cell" else "atom");
+                q_gal  (* Execute the formula, ignore hint *)
               end
             in
             nock_on bus nex